The present invention relates to a new and distinct variety of sweet orange tree named ‘OLL-8’. ‘OLL-8’ is a somaclone regenerated from embryogenic callus (tissue culture) of ‘Orie Lee Late’ (‘OLL’) sweet orange (unpatented), with high-quality fruit that usually matures in the standard ‘Valencia’ (unpatented) time period. ‘OLL’ is believed to be an irradiation-induced mutant line originating from Pineapple sweet orange in an abandoned USDA trial attempting to generate a seedless Pineapple orange. ‘OLL’ attracted attention because it never dropped fruit, a serious problem with Pineapple, and held quality late into the summer. Propagations of ‘OLL’ were not uniform and included some trees of poor growth and productivity, as well as robust high-yielding trees. In efforts to generate genetically stable clones from the ‘OLL’ selection, tissue cultures (embryogenic callus) were established for the creation of somaclones. ‘OLL-8’ was the most precocious bearing tree among the population of somaclones regenerated. Trueness-to-type of ‘OLL-8’ was demonstrated by topworking two trees to Swingle citrumelo rootstock in CREC Block 18-North 40. Topworked trees are stable and productive, producing true-to-type fruit (for 4 consecutive years). In addition, young trees propagated on various rootstocks are stable and produce true-to-type fruit at multiple trial locations. ‘OLL-8’ was first asexually reproduced in Lake Alfred, Polk County, Fla., by topworking. The first asexually reproduced trees were originally Duncan grapefruit on Swingle citrumelo rootstock, topworked with ‘OLL-8’. Since this time, hundreds of trees have been asexually propagated on multiple rootstocks using standard nursery practices. All asexually reproduced trees have been true-to-type to date.